Automatic ash level control mechanism for gas producer units



ay9, 1950 .1. FALLON 2,506,782

AUTOMATIC ASH LEVEL CONTROL MECHANISM FOR GAS PRODUCER UNITS Filed May 20, 1946 2 'sheets-sheet 1 y @www ay 9, 1950 J. FALLON 2,506,782

AUTOMATIC ASH LEVEL CONTROL MECHANISM FOR GAS PRODUCER UNITS Filed May 20, 1946 2 Sheets-Sheet 2 Q FW l). yCi/QWW//ypm om@ 5 Patented May 9, 1950 UNITED AUTOMATIC ASH LEVEL CONTROL MECHA- NISM FOR GAS PRODUCER UNITS John Fallon, Smethwick, England Application May 20, 1946, Serial No. 670,940 In Great Britain May 21, 1945 2 Claims. l

This invention has reference to an improved gas producer unit adapted for automatic control.

The primary object of the present invention is to construct what may be termed a self-contained gas producer unit which is automatically controlled in accordance with the rate of fuel consumption and consequent rate of gasification so as to avoid the necessity for individual or personal control of the unit when the requisite conditions have been established whereby the unit may continue to be operated with a minimum amount of observation or inspection.

The invention consists of a gas producer unit wherein the rate of ash discharge is automatically governed by means controlled by the temperature of the ash zone, said discharge rate being co-related to feeler means for determining the operation of the fuel supply mechanism.

One means of carrying the present invention into practice will now be described with particular reference to the accompanying drawings, in which:

Fig. 1 is a sectional elevation through the apparatus,

Fig. 2 is a part sectional plan on line S2-2 of Fig. 1.

Fig. 3 is a schematic wiring diagram of the inter-relationship between temperature sensing means located in the ash Zone of the gas producer unit and the motive power for controlling the ash discharge rate.

The unit comprises a furnace chamber a part of which al is water jacketed; below the water jacketed section is the base b of the chamber in which is rotatably mounted a truncated conical retort c provided with tuyres c2, the sides of the retort being inwardly inclined at the upper part thereof to form a truncated conical receptacle which terminates in a neck c1 and is thenextended to a flared outlet which leads to a discharge aperture b1 disposed to one side of the base containing the rotatable retort c. The retort is mounted on idle rollers d and rotatably traversed thereon through the medium of a geared power-operated transmission generally designated e driven by a motor h.

The primary feature of the present invention resides in the provision within the necked outlet from the retort c of a hollow tube f closed at its upper end which tube projects upwardly into the body of the retort on a line which is eccentrically disposed with respect to the vertical axis of the retort. This tube contains a thermo-couple or thermostat g which registers or is governed by the temperature of the zone in which the tube is located and it is to be appreciated that this temperature will vary in accordance with the ash level of the retort c i. e. if the ash level rises the zone contiguous to the tube f will cool, While if the ash level falls then a greater heat zone will obtain in the neighbourhood of the tube within the retort.

This variation of temperature is automatically communicated by the thermo-couple or thermostat g within the tube f through flexible leads or other means (not shown) to a relay control instrument which may incorporate a magnetic coil or electro-magnet, this device is connected to and determines the speed of rotation of the motor h. or other power drive mechanism operating a pug screw 7 which serves to positively eject the ash from the aperture b1 below the retort c into the delivery pipe lc. In Fig. 3 the wiring between the thermostat y which is located within the protective tube f and the motor h is schematically indicated. When the temperature within the ash bed reaches a predetermined point the thermostatic elements close the circuit to the motor and the frusto-conical retort c is rotated sifting the ashes downwardly into the delivery pipe lc from which they are ejected by the screw fi. By this means it will be appreciated that the temperature of the ash content governed by the quantity and condition thereof automatically determines the speed of discharge or ejection of the ash from the unit.

This operation is co-related to an automatically controlled fuel supply mechanism which forms a part of the complete unit, this fuel supply mechanism comprises a feed hopper Z, the outlet from which is governed by a rotatable multi-compartmented drum m which is intermittently rotated through a linkage to be hereinafter described, the operation being governed by the height of the top surface of the fuel bed.

The fuel bed within the upper part of the furnace chamber a has normally resting thereon a feeler plate n which is mounted at the lower end of a vertical reciprocatory spindle o. This feeler plate is adapted to be brought into contact intermittently and periodically with the top surface of the fuel bed so that when the level of the fuel bed falls below a predetermined minimum the drum m is partially rotated to eject from one of the compartments thereof the supply of fuel which has been fed thereinto from the feed hopper l.

The spindle o is suspended with a sleeve p from the free ends of a chain q engaged with a sprocket wheel r. The sprocket wheel r is mounted for 3 revolution around a shaft s, being rotatably mounted at the end of a crank s1, whereby the sprocket r is moved through a circular path as indicated by the chain line r1 in Fig. 1. This movement causes a periodic lowering and raising motion of the sleeve p, spindle o and feeler plate n. The chain q has an adjustable connection to the sleeve p to take up slack between the axle of the sprocketwheel r and the feeler plate n. The sleeve p on its lowering motion makes contact at its lower end with the rocker arm t mounted on the spindle t1, the collar u keyed to the spindle o serving to return the rocker arm *t on the upstroke of the spindle o. The sleeve :o can slide independently on the spindle o shouldthe top-surface of the fuel bed be at or above normal whenever a lowering motion is communicated V'to the chain q and the sleeve q suspended therefrom, thus avoiding a rotational motion of the drum m.

The rocker arm t is associated through the Vspindle t1 with yan arm i) which vat its upper end carries the link rod w which at its other end is connected to the arm :c which is keyed to the Yspindle of the drum m and serves to effect through a pawl and ratchet toothed mechanism y an intermittent progressive rotational motion to the drum m so that the position of the surface ofthe fuel bed within the furnace chamber determines through the aforesaid mechanism the rate of feed ofthe fuel from the hopper-Z through the rotatable compartmented drum m into the fuel chamber.

The shaft s is driven by a motor which is not shown in the drawings, or from any other convenient sourceicf power drive.

rPhe furnace chamber a is provided with a separable cover a2 adapted to be bolted'thereto, from which cover extends the gas outlet conduit a3.

From the foregoing description it will be apprecriated that if the fuel bed reaches a lower level than is normal under the predetermined opera- -tive conditions that an increase inthe temperature of the fuel Zone about the upper end of the tube f will obtain and therefore the electromotive force generated in the thermo-.couple located Within the tube or connected thereto will result in a cessation or slowing down of the ash discharge mechanismi. e. a slowing down of the rotation of the pug screw y' and that in consequence the subsequent operation of the feeler plate n will result in a supply of fuel to the furnace from the compartmented drum m through themedium of 'the inter-connected transmission linkage comprising the spindle o, sleeve p, chain q, rocker arm t, arm o, link rod w, arm a: and pawl and ratchet drive y to the drum m; While on the other hand if the Afuel bed rises to a level which causes the upper end of'thetube f to cool then the ash discharge mechanism is automatically re-started or speeded up to correspond to the combustion conditions obtaining within the furnace chamber, thus the fuel supply to the bed and the ash discharge from the lower level of this bed is automatically controlled according to the level and temperature conditions of the bed.

The furnace is provided with a controlled air blast in accordance with recognised producer gas practice, the air blast being discharged under and through the rotating grate c entering the grate through the conduit a. This blast may be regulated and controlled by a thermostatically or pyrometrically operated valve .el co-related to the 'temperature of the furnace -into lwhich the gas from theproducer is supplied.

I claim:

1. In a gas producing furnace having a vertically extending combustion chamber, an auto- 'inatic 'fuel level control mechanism and means 4for'su'pplying'fuel at the upper part of the furnace Vcombustion chamber under control of said mechanism, an ash discharge control device comprising an inverted rotatable, vertically extending, subs`t'ani'ii'a'll'y'frusto-conical retort having a centrally located opening at its apex, a thermally responsive unit extending upwardly through such opening in said retort and a substantial distance into the ash Zone iocated therein, porter-operated means for removing ashes Yfrom beneath said retort, and power-operated means for rotating said retort, both of said power-operated means being controlled by said vthermally responsive unit for sifting ashes through said retort by rotation thereof .and for removing ashes from beneath said retort in response to rpredetermined changes in temperature in the ash bed located within said retort.

2. Ash bed control mechanism for a solid fuel burning, vertical chamber'furnace comprising, in combination, an inverted rotatable, vertically extending, substantially frus'to-conical retort having 'a downwardly directed,'tiuncated, open apex, a thermally responsive unit extending upwardly through the open apex df s-aidretort and a substantial dista-nce'iritothe'ash zonelocated therein, a horizontally extending 4base .plate 4beneath said retort, said base Vp'la'te having .an ash-passage opening therein, "a 'discharge wornfi located 'beneath the opening in said base lplate forremoving ashes, vand po'wer'mea'n'sjfor "rotating said retort `and for driving said worm, said power means being responsive to said theimally'responsive unit whereby the level of the ash bed and the discharge of ash from's'aid furnace 'is correlated to temperatures inthe ash'be'd.

JOHN 'FALLON REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 'Name VDate 1,862,477 Gralusha June 7, 1932 1,863,677 Vodoz June 21,1932 1,887,758 Maloney Nov. 15, 1932 1,984,852 Vo'doz 1'8, 1934 2,022,716 Grimeetal Dec. 3, 1935 2,074,431 Reid, Jr Mar. 23, 1937 2,118,651 Macchi May 24, 1933 2,243,970 Lower June 3, 1941 

